AuthorTopic: Possible New Filter Design (Read 22100 times)

I use quite a few XPPF filters and several AF-120 filters. This filter looks like it would cover more problems than the AF-120 at enough current for some of the bigger loads like UPS units, home theater power buss, etc. up to maybe 1,000 watts? I have smoked a few XPPF filters at what I thought were acceptable current levels. Jeff, I guess you will post if and when you decide?

There have been several requests for a higher current version of the XTB-F10, and I will be offering a 15A version. The in-band filtering of both filters is similar, but the out-of-band performance of the F10 is slightly better because of its lower Q. That is a function of the values available for the higher current inductors.

The higher current version does not contain an internal fuse. Actually, the inductors are rated in excess of 15A, and the limit is due to the AC receptacle itself. (There is not sufficient clearance for two receptacles on the cover.)

Looking at the fuse curves, higher current fuses don't really offer much protection. It takes a lot of heat to melt the heavy conductor in the high-current fuses, and they dissipate about 4W at max current. Both 15A slow-blow and fast-blow fuses will typically pass 30A for 1000 seconds before they pop. Since a 15A fuse doesn't offer as much protection as a typical circuit breaker feeding the circuit, I chose to eliminate the fuse and save the dissipation.

There are duplicate traces on both sides for the high current paths. The first run of PCBs has 1 ounce copper, which is rated for 10C rise at 14A at that trace width. That is less than the temperature rise in the inductors at max current. The 15A version has 4 ounce copper, and the temperature rise at max current will be insignificant.